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Fusco FB, Gomes DJ, Bispo KCS, Toledo VP, Barbeiro DF, Capelozzi VL, Furukawa LNS, Velosa APP, Teodoro WR, Heimann JC, Quintao ECR, Passarelli M, Nakandakare ER, Catanozi S. Low-sodium diet induces atherogenesis regardless of lowering blood pressure in hypertensive hyperlipidemic mice. PLoS One 2017; 12:e0177086. [PMID: 28481921 PMCID: PMC5421755 DOI: 10.1371/journal.pone.0177086] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 04/21/2017] [Indexed: 12/21/2022] Open
Abstract
This study investigated the influence of sodium restriction and antihypertensive drugs on atherogenesis utilizing hypertensive (H) low-density lipoprotein-receptor knockout mice treated or not with losartan (Los) or hydralazine (Hyd) and fed low-sodium (LS) or normal-sodium (NS) chow. Despite reducing the blood pressure (BP) of H-LS mice, the LS diet caused arterial lipid infiltration due to increased plasma total cholesterol (TC) and triglycerides (TG). Los and Hyd reduced the BP of H-LS mice, and Los effectively prevented arterial injury, likely by reducing plasma TG and nonesterified fatty acids. Aortic lipid infiltration was lower in Los-treated H-LS mice (H-LS+Los) than in normotensive (N)-LS and H-LS mice. Aortic angiotensin II type 1 (AT1) receptor content was greater in H-NS than H-LS mice and in H-LS+Hyd than H-LS+Los mice. Carboxymethyl-lysine (CML) and receptor for advanced glycation end products (RAGE) immunostaining was greater in H-LS than H-NS mice. CML and RAGE levels were lower in LS animals treated with antihypertensive drugs, and Hyd enhanced the AT1 receptor level. Hyd also increased the gene expression of F4/80 but not tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-10, intercellular adhesion molecule-1 or cluster of differentiation 66. The novelty of the current study is that in a murine model of simultaneous hypertension and hyperlipidemia, the pleiotropic effect of chronic, severe sodium restriction elicited aortic damage even with reduced BP. These negative effects on the arterial wall were reduced by AT1 receptor antagonism, demonstrating the influence of angiotensin II in atherogenesis induced by a severely LS diet.
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Affiliation(s)
- Fernanda B. Fusco
- Lipids Laboratory (LIM-10) of Endocrinology Division of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Diego J. Gomes
- Lipids Laboratory (LIM-10) of Endocrinology Division of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Kely C. S. Bispo
- Department of Pathology of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Veronica P. Toledo
- Rheumatology Division (LIM-17) of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Denise F. Barbeiro
- Emergency Medicine Department (LIM-51) of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Vera L. Capelozzi
- Department of Pathology of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Luzia N. S. Furukawa
- Experimental Hypertension Laboratory (LIM-16) of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Ana P. P. Velosa
- Rheumatology Division (LIM-17) of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Walcy R. Teodoro
- Rheumatology Division (LIM-17) of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Joel C. Heimann
- Experimental Hypertension Laboratory (LIM-16) of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Eder C. R. Quintao
- Lipids Laboratory (LIM-10) of Endocrinology Division of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Marisa Passarelli
- Lipids Laboratory (LIM-10) of Endocrinology Division of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Edna R. Nakandakare
- Lipids Laboratory (LIM-10) of Endocrinology Division of the University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Sergio Catanozi
- Lipids Laboratory (LIM-10) of Endocrinology Division of the University of São Paulo Medical School, São Paulo, SP, Brazil
- * E-mail:
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Geraldes V, Goncalves-Rosa N, Tavares C, Paton JFR, Rocha I. Reversing gene expression in cardiovascular target organs following chronic depression of the paraventricular nucleus of hypothalamus and rostral ventrolateral medulla in spontaneous hypertensive rats. Brain Res 2016; 1646:109-115. [PMID: 27238462 DOI: 10.1016/j.brainres.2016.05.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 05/21/2016] [Accepted: 05/23/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Chronic overexpression of an inwardly rectifying potassium channel (hKir2.1) in the paraventricular nucleus of the hypothalamus (PVN) and in the rostral ventrolateral medulla (RVLM) to suppress neuronal excitability, resulted in a long term decrease of blood pressure and sympathetic output in spontaneously hypertensive rats (SHR). OBJECTIVE Evaluate gene expression in end-organs of SHR after a chronic overexpression of hKir2.1 channels in either the PVN or RVLM. METHODS mRNA levels of 16 genes known to be involved with blood pressure regulation were evaluated using RT-PCR in tissues from the heart, common carotid artery and kidney of SHR submitted to chronic depression of PVN and RVLM excitability using a lentiviral vector (LVhKir2.1). RESULTS In SHR hearts in which either the PVN or RVLM were injected with LVhKir2.1, there was a downregulation of angiotensin II receptor 1b (AT1), ATPase, Ca(2+)-transporter, troponin T2 and tropomyosin2 (only in RVLM) relative to the sham group. In the kidney of SHR with LVhKir2.1 injections in PVN and RVLM, angiotensinogen, angiotensin II receptor2 (AT2) and endothelin1 were all upregulated compared to sham. In the carotid artery, endothelin2, endothelin receptor A and B were up-regulated following LVhKir2.1 in to either the PVN or RVLM relative to sham. CONCLUSION Chronic overexpression of hKir2.1 channels in PVN and RVLM, promoted a BP decrease with up-regulation of angiotensinogen and AT2 genes expression in the kidney and down-regulation of AT1 in the heart of SHR. Thus, we demonstrate the potential efficacy of central manipulation to protect against end-organ damage in essential hypertension.
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Affiliation(s)
- Vera Geraldes
- Institute of Physiology, Faculty of Medicine and Cardiovascular Centre of University of Lisbon, Portugal
| | - Nataniel Goncalves-Rosa
- Institute of Physiology, Faculty of Medicine and Cardiovascular Centre of University of Lisbon, Portugal
| | - Cristiano Tavares
- Institute of Physiology, Faculty of Medicine and Cardiovascular Centre of University of Lisbon, Portugal
| | - Julian F R Paton
- School of Physiology & Pharmacology, Biomedical Sciences, University of Bristol, Bristol, UK
| | - Isabel Rocha
- Institute of Physiology, Faculty of Medicine and Cardiovascular Centre of University of Lisbon, Portugal.
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Akarsu M, Saygun O, Aydinuraz K, Aydin O, Daphan CE, Tanrıkulu FB, Kisa U, Comu FM. The Effects of Simvastatin on Ischemia Reperfusion Injury in an Experimental Colon Anastomosis Model. Indian J Surg 2016; 79:390-395. [PMID: 29089696 DOI: 10.1007/s12262-016-1493-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 04/28/2016] [Indexed: 11/28/2022] Open
Abstract
Anastomotic leakage is more frequently reported in colonic anastomoses. Ischemia reperfusion injury is one of the main reasons for anastomotic leakage. Simvastatin is known to prevent tissue damage induced by free oxygen radicals after ischemia reperfusion injury. The effect of simvastatin on colonic anastomosis impaired by ischemia reperfusion injury is investigated. Single layer, end-to-end colocolic anastomosis after 0.5-cm colon resection was performed in Wistar Albino rats. In Group 1 (control) (n = 10), colonic anastomosis without I-R was performed. In Group 2 (n = 10), the superior mesenteric artery was clamped for 10 min followed by 60 min of reperfusion after which resection anastomosis was performed. In Group 3 (n = 10), 10 mg/kg simvastatin was given by gavage for 7 days after I-R and resection anastomosis. In Group 4 (n = 10), the rats received 10 mg/kg simvastatin by gavage 7 days before and 7 days after ischemia reperfusion and surgery. All of the rats were sacrificed 8 days after surgery. Anastomotic bursting pressure and tissue hydroxyproline levels were measured. Postoperative administration of simvastatin restored the anastomotic bursting pressure and hydroxyproline levels to that of control group thus overcoming the effect of ischemia reperfusion injury. Simvastatin administered postoperatively in an experimental model of colonic resection anastomosis impaired by ischemia reperfusion injury increased anastomotic bursting pressures and tissue hydroxyproline levels. Further experimental and clinical studies will show whether administration of simvastatin will increase reliability of the anastomosis and decrease postoperative morbidity and mortality in colonic anastomosis after ischemia reperfusion injury.
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Affiliation(s)
- Mahmut Akarsu
- Department of General Surgery, Medical Faculty, Kırıkkale University, Kırıkkale, Turkey
| | - Oral Saygun
- Department of General Surgery, Medical Faculty, Kırıkkale University, Kırıkkale, Turkey
| | - Kuzey Aydinuraz
- Department of General Surgery, Medical Faculty, Kırıkkale University, Kırıkkale, Turkey
| | - Oktay Aydin
- Department of General Surgery, Medical Faculty, Kırıkkale University, Kırıkkale, Turkey
| | - Cagatay Erden Daphan
- Department of General Surgery, Medical Faculty, Kırıkkale University, Kırıkkale, Turkey
| | | | - Ucler Kisa
- Department of Biochemistry, Medical Faculty, Kırıkkale University, Kırıkkale, Turkey
| | - Faruk Metin Comu
- Department of Physiology, Medical Faculty, Kırıkkale University, Kırıkkale, Turkey
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Carillon J, Gauthier A, Barial S, Tournier M, Gayrard N, Lajoix AD, Jover B. Relaxin and atrial natriuretic peptide pathways participate in the anti-fibrotic effect of a melon concentrate in spontaneously hypertensive rats. Food Nutr Res 2016; 60:30985. [PMID: 27079780 PMCID: PMC4832218 DOI: 10.3402/fnr.v60.30985] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/04/2016] [Accepted: 03/17/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In spontaneously hypertensive rats (SHR), a model of human essential hypertension, oxidative stress is involved in the development of cardiac hypertrophy and fibrosis associated with hypertension. Dietary supplementation with agents exhibiting antioxidant properties could have a beneficial effect in remodeling of the heart. We previously demonstrated a potent anti-hypertrophic effect of a specific melon (Cucumis melo L.) concentrate with antioxidant properties in spontaneously hypertensive rats. Relaxin and atrial natriuretic peptide (ANP) were reported to reduce collagen deposition and fibrosis progression in various experimental models. OBJECTIVE The aim of the present investigation was to test the hypothesis that, beside reduction in oxidative stress, the melon concentrate may act through relaxin, its receptor (relaxin/insulin-like family peptide receptor 1, RXFP1), and ANP in SHR. DESIGN AND RESULTS The melon concentrate, given orally during 4 days, reduced cardiomyocyte size (by 25%) and totally reversed cardiac collagen content (Sirius red staining) in SHR but not in their normotensive controls. Treatment with the melon concentrate lowered cardiac nitrotyrosine-stained area (by 45%) and increased by 17-19% the cardiac expression (Western blot) of superoxide dismutase (SOD) and glutathione peroxidase. In addition, plasma relaxin concentration was normalized while cardiac relaxin (Western blot) was lowered in treated SHR. Cardiac relaxin receptor level determined by immunohistochemical analysis increased only in treated SHR. Similarly, the melon concentrate reversed the reduction of plasma ANP concentration and lowered its cardiac expression. CONCLUSIONS The present results demonstrate that reversal of cardiac fibrosis by the melon concentrate involves antioxidant defenses, as well as relaxin and ANP pathways restoration. It is suggested that dietary SOD supplementation could be a useful additional strategy against cardiac hypertrophy and fibrosis.
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Affiliation(s)
- Julie Carillon
- EA7288 Université de Montpellier, Montpellier, France.,Bionov Research, Montpellier, France
| | | | - Sandy Barial
- EA7288 Université de Montpellier, Montpellier, France
| | | | | | | | - Bernard Jover
- EA7288 Université de Montpellier, Montpellier, France;
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Ma Y, Kong L, Qi S, Wang D. Atorvastatin blocks increased l-type Ca2+ current and cell injury elicited by angiotensin II via inhibiting oxide stress. Acta Biochim Biophys Sin (Shanghai) 2016; 48:378-84. [PMID: 26940997 DOI: 10.1093/abbs/gmw009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 12/12/2015] [Indexed: 12/13/2022] Open
Abstract
Thel-type Ca(2+)current (ICa,l) plays a crucial role in shaping action potential and is involved in cardiac arrhythmia. Statins have been demonstrated to contribute to anti-apoptotic and anti-arrhythmic effects in the heart. Here, we examined whether atorvastatin regulates theICa,land cell injury induced by angiotensin II (AngII) as well as the putative intracellular cascade responsible for the effects. Cultured neonatal rat ventricular myocytes were incubated with AngII for 24 h, and then cell injury and expression levels of Nox2/gp91(phox), p47(phox) ,and Cav1.2 were analyzed. In addition,ICa,lwas recorded using the whole-cell patch-clamp technique, and mechanisms of atorvastatin actions were also investigated. It was found that the number of apoptotic cardiomyocytes was increased and cell viability was significantly decreased after AngII administration. AngII also augmented the expressions of Nox2/gp91(phox)and p47(phox)compared with control cardiomyocytes. Exposure to AngII evokedICa,lin a voltage-dependent manner without affecting theI-Vrelationship. In addition, AngII enhanced membrane Cav1.2 expression. These effects were abolished in the presence of the reactive oxygen species (ROS) scavenger, manganese (III)-tetrakis 4-benzoic acid porphyrin [Mn(III)TBAP], or the 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor, atorvastatin. These results suggested that atorvastatin mediates cardioprotection against arrhythmias and cell injury by controlling the AngII-ROS cascade.
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Affiliation(s)
- Yanzhuo Ma
- Department of Cardiology, Bethune International Peace Hospital, Shijiazhuang 050000, China
| | - Lingfeng Kong
- Department of Cardiology, Bethune International Peace Hospital, Shijiazhuang 050000, China Hebei Medical University, Shijiazhuang 050011, China
| | - Shuying Qi
- Department of Cardiology, Bethune International Peace Hospital, Shijiazhuang 050000, China
| | - Dongmei Wang
- Department of Cardiology, Bethune International Peace Hospital, Shijiazhuang 050000, China
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Bitto A, Bagnato GL, Pizzino G, Roberts WN, Irrera N, Minutoli L, Russo G, Squadrito F, Saitta A, Bagnato GF, Altavilla D. Simvastatin prevents vascular complications in the chronic reactive oxygen species murine model of systemic sclerosis. Free Radic Res 2016; 50:514-22. [PMID: 26846205 DOI: 10.3109/10715762.2016.1149171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Aims Systemic sclerosis (SSc) is characterized by vasculopathy and organ fibrosis. Although microvascular alterations are very well characterized, structural and functional abnormalities of large vessels are not well defined. Therefore, we evaluated the effect of simvastatin administration on aortic and small renal arteries thickening, and on myofibroblasts differentiation in a murine model of SSc. Methods and results SSc was induced in BALB/c mice by daily subcutaneous injections of hypochlorous acid (HOCl, 100 μl) for 6 weeks. Mice (n = 23) were randomized to receive: HOCl (n = 10); HOCl plus simvastatin (40 mg/kg; n = 8); or vehicle (n = 5). Simvastatin administration started 30 min after HOCl injection, and up to week 6. Aortic and small renal arteries intima-media thickness was evaluated by histological analysis. Immunostaining for α-smooth muscle actin (SMA), vascular endothelial growth factor receptor 2 (VEGFR2), and CD31 in aortic tissues was performed to evaluate myofibroblast differentiation and endothelial markers.In HOCl-treated mice, intima-media thickening with reduced lumen diameter was observed in the aorta and in small renal arteries and simvastatin administration prevented this increase. Aortic and renal myofibroblasts count, as expressed by α-SMA + density, was lower in the group of mice treated with simvastatin compared to HOCl-treated mice. Simvastatin prevented the reduction in VEGFR2 and CD31 expression induced by HOCl. Conclusions The administration of simvastatin regulates collagen deposition in the aortic tissues and in the small renal arteries by modulating myofibroblasts differentiation and vascular markers. Further studies are needed to better address the effect of statins in the macrovascular component of SSc.
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Affiliation(s)
- Alessandra Bitto
- a Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | - Gian Luca Bagnato
- a Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | - Gabriele Pizzino
- a Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | | | - Natasha Irrera
- a Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | - Letteria Minutoli
- a Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | - Giuseppina Russo
- a Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | - Francesco Squadrito
- a Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | - Antonino Saitta
- a Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | - Gian Filippo Bagnato
- a Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | - Domenica Altavilla
- c Department of Paediatric, Gynaecological, Microbiological and Biomedical Sciences , University of Messina , Messina , Italy
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Activities of apocynin in cytotoxicity assays of potential pathological relevance. Biomed Pharmacother 2015; 76:6-10. [DOI: 10.1016/j.biopha.2015.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 09/21/2015] [Accepted: 10/15/2015] [Indexed: 11/22/2022] Open
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Brand S, Amann K, Mandel P, Zimnol A, Schupp N. Oxidative DNA damage in kidneys and heart of hypertensive mice is prevented by blocking angiotensin II and aldosterone receptors. PLoS One 2014; 9:e115715. [PMID: 25551569 PMCID: PMC4297153 DOI: 10.1371/journal.pone.0115715] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 11/28/2014] [Indexed: 12/24/2022] Open
Abstract
Introduction Recently, we could show that angiotensin II, the reactive peptide of the blood pressure-regulating renin-angiotensin-aldosterone-system, causes the formation of reactive oxygen species and DNA damage in kidneys and hearts of hypertensive mice. To further investigate on the one hand the mechanism of DNA damage caused by angiotensin II, and on the other hand possible intervention strategies against end-organ damage, the effects of substances interfering with the renin-angiotensin-aldosterone-system on angiotensin II-induced genomic damage were studied. Methods In C57BL/6-mice, hypertension was induced by infusion of 600 ng/kg • min angiotensin II. The animals were additionally treated with the angiotensin II type 1 receptor blocker candesartan, the mineralocorticoid receptor blocker eplerenone and the antioxidant tempol. DNA damage and the activation of transcription factors were studied by immunohistochemistry and protein expression analysis. Results Administration of angiotensin II led to a significant increase of blood pressure, decreased only by candesartan. In kidneys and hearts of angiotensin II-treated animals, significant oxidative stress could be detected (1.5-fold over control). The redox-sensitive transcription factors Nrf2 and NF-κB were activated in the kidney by angiotensin II-treatment (4- and 3-fold over control, respectively) and reduced by all interventions. In kidneys and hearts an increase of DNA damage (3- and 2-fold over control, respectively) and of DNA repair (3-fold over control) was found. These effects were ameliorated by all interventions in both organs. Consistently, candesartan and tempol were more effective than eplerenone. Conclusion Angiotensin II-induced DNA damage is caused by angiotensin II type 1 receptor-mediated formation of oxidative stress in vivo. The angiotensin II-mediated physiological increase of aldosterone adds to the DNA-damaging effects. Blocking angiotensin II and mineralocorticoid receptors therefore has beneficial effects on end-organ damage independent of blood pressure normalization.
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Affiliation(s)
- Susanne Brand
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany
| | - Kerstin Amann
- Department of Pathology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Philipp Mandel
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany
| | - Anna Zimnol
- Institute of Toxicology, University of Düsseldorf, Düsseldorf, Germany
| | - Nicole Schupp
- Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany
- Institute of Toxicology, University of Düsseldorf, Düsseldorf, Germany
- * E-mail:
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Pro-oxidative effects of aggregated transthyretin in human Schwannoma cells. Neurotoxicology 2013; 39:109-13. [DOI: 10.1016/j.neuro.2013.08.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 08/01/2013] [Accepted: 08/13/2013] [Indexed: 01/21/2023]
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Kim EY, Anderson M, Wilson C, Hagmann H, Benzing T, Dryer SE. NOX2 interacts with podocyte TRPC6 channels and contributes to their activation by diacylglycerol: essential role of podocin in formation of this complex. Am J Physiol Cell Physiol 2013; 305:C960-71. [PMID: 23948707 DOI: 10.1152/ajpcell.00191.2013] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Canonical transient receptor potential-6 (TRPC6) channels have been implicated in the pathophysiology of glomerular diseases. TRPC6 channels are typically activated by diacylglycerol (DAG) during PLC-dependent transduction cascades. TRPC6 channels can also be activated by reactive oxygen species (ROS). We previously showed that podocin is required for DAG analogs to produce robust activation of TRPC6 channels in podocytes. Here we show that endogenous TRPC6 channels in immortalized podocytes reciprocally coimmunoprecipitate with the catalytic subunit of the NADPH oxidase NOX2 (gp91(phox)). The NOX2-TRPC6 interaction was not detected in cells stably expressing a short hairpin RNA targeting podocin, although NOX2 and TRPC6 were present at normal levels. Application of a membrane-permeable DAG analog [1-oleoyl-2-acetyl-sn-glycerol (OAG)] increased generation of ROS in podocytes, but this effect was not detected in podocin knockdown cells. OAG also increased steady-state surface expression of the NOX2 regulatory subunit p47(phox). In whole cell recordings, TRPC6 activation by OAG was reduced in podocytes pretreated with the NOX2 inhibitor apocynin, by the pan-NOX inhibitor diphenylene iodonium, and by tempol, a ROS quencher. Cholesterol depletion and disruption of lipid rafts by methyl-β-cyclodextrin reduced activation of podocyte TRPC6 channels by OAG and also eliminated the NOX2-TRPC6 interaction as assessed by coimmunoprecipitation. These data suggest that active NOX2 assembles with TRPC6 at podocin-organized sterol-rich raft domains and becomes catalytically active in response to DAG. The localized production of ROS contributes to TRPC6 activation by chemical stimuli such as DAG. Podocin appears to be necessary for assembly of the NOX2-TRPC6 complex in lipid rafts.
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Affiliation(s)
- Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
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Bernardes N, Brito JO, Fernandes TG, Llesuy SF, Irigoyen MC, Belló-Klein A, De Angelis K. Pleiotropic effects of simvastatin in physically trained ovariectomized rats. Braz J Med Biol Res 2013; 46:447-53. [PMID: 23739748 PMCID: PMC3854401 DOI: 10.1590/1414-431x20122111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 11/14/2012] [Indexed: 11/22/2022] Open
Abstract
This study tested the hypothesis that simvastatin treatment can improve
cardiovascular and autonomic functions and membrane lipoperoxidation, with an
increased effect when applied to physically trained ovariectomized rats.
Ovariectomized rats were divided into sedentary, sedentary+simvastatin and
trained+simvastatin groups (n = 8 each). Exercise training was
performed on a treadmill for 8 weeks and simvastatin (5 mg/kg) was
administered in the last 2 weeks. Blood pressure (BP) was recorded in conscious
animals. Baroreflex sensitivity was evaluated by the tachycardic and bradycardic
responses to BP changes. Cardiac vagal and sympathetic effects were determined
using methylatropine and propranolol. Oxidative stress was evaluated based on
heart and liver lipoperoxidation using the chemiluminescence method. The
simvastatin-treated groups presented reduced body weight and mean BP
(trained+simvastatin = 99 ± 2 and sedentary+simvastatin
= 107 ± 2 mmHg) compared to the sedentary group (122
± 1 mmHg). Furthermore, the trained group showed lower BP and
heart rate compared to the other groups. Tachycardic and bradycardic responses
were enhanced in both simvastatin-treated groups. The vagal effect was increased
in the trained+simvastatin group and the sympathetic effect was decreased
in the sedentary+simvastatin group. Hepatic lipoperoxidation was reduced in
sedentary+simvastatin (≈21%) and trained+simvastatin
groups (≈57%) compared to the sedentary group. Correlation
analysis involving all animals demonstrated that cardiac lipoperoxidation was
negatively related to the vagal effect (r = -0.7) and positively
correlated to the sympathetic effect (r = 0.7). In conclusion,
improvement in cardiovascular and autonomic functions associated with a
reduction of lipoperoxidation with simvastatin treatment was increased in
trained ovariectomized rats.
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Affiliation(s)
- N Bernardes
- Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brasil
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Fong VH, Vieira A. Transthyretin aggregates induce production of reactive nitrogen species. NEURODEGENER DIS 2012; 11:42-8. [PMID: 22627469 DOI: 10.1159/000338153] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 03/19/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Misfolded and aggregated transthyretins (agTTR) contribute to neurodegenerative amyloid diseases such as familial amyloid polyneuropathy and senile systemic amyloidosis. The neurotoxicity mechanisms of agTTR, however, are not well understood. In the current study, the possible contribution of reactive nitrogen species (RNS) to such mechanisms was investigated by examining agTTR-mediated changes in cellular RNS levels. METHODS AND RESULTS The production of RNS was assessed through nitrate and nitrite assays in two human cell lines after exposure to agTTR (2.4 µM pre-aggregation concentration). In both epidermoid (A431) and schwannoma (sNF94.3) cell lines, agTTR induced significant increases in RNS (p < 0.05 relative to the same concentration of normal TTR, or no-TTR controls). Redox modulators such as apocynin (1-(4-hydroxy-3-methoxy-phenyl)ethanone) and L-NMMA (N(G)-monomethyl-L-arginine) were tested for their effects on RNS production. These modulators decreased RNS production in both cell lines; although the effects of L-NMMA were statistically significant only in the schwannoma cells. Moreover, cells treated with agTTR exhibited decreases in metabolic activity relative to TTR- or non-TTR-treated cells (p < 0.05) as assessed by reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). CONCLUSION The results provide novel evidence for involvement of RNS in pro-oxidative effects of agTTR in two different human cell lines, and show that agTTR can induce more generalized changes in cellular metabolic activity.
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Affiliation(s)
- Vai-Hong Fong
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
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Aiassa V, Baronetti J, Paez P, Barnes A, Albrecht C, Pellarin G, Eraso A, Albesa I. Increased advanced oxidation of protein products and enhanced total antioxidant capacity in plasma by action of toxins of Escherichia coli STEC. Toxicol In Vitro 2011; 25:426-31. [DOI: 10.1016/j.tiv.2010.11.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/08/2010] [Accepted: 11/09/2010] [Indexed: 11/28/2022]
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14
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Maheshwari M, Roberts JK, DeSutter B, Duong K, Tingling J, Fawver JN, Schall HE, Kahle M, Murray IV. Hydralazine modifies Aβ fibril formation and prevents modification by lipids in vitro. Biochemistry 2010; 49:10371-80. [PMID: 21058733 PMCID: PMC3033120 DOI: 10.1021/bi101249p] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lipid oxidative damage and amyloid β (Aβ) misfolding contribute to Alzheimer's disease (AD) pathology. Thus, the prevention of oxidative damage and Aβ misfolding are attractive targets for drug discovery. At present, no AD drugs approved by the Food and Drug Administration (FDA) prevent or halt disease progression. Hydralazine, a smooth muscle relaxant, is a potential drug candidate for AD drug therapy as it reduces Aβ production and prevents oxidative damage via its antioxidant hydrazide group. We evaluated the efficacy of hydralazine, and related hydrazides, in reducing (1) Aβ misfolding and (2) Aβ protein modification by the reactive lipid 4-hydroxy-2-nonenal (HNE) using transmission electron microscopy and Western blotting. While hydralazine did not prevent Aβ aggregation as measured using the protease protection assay, there were more oligomeric species observed by electron microscopy. Hydralazine prevented lipid modification of Aβ, and Aβ was used as a proxy for classes of proteins which either misfold or are modified by HNE. All of the other hydrazides prevented lipid modification of Aβ and also did not prevent Aβ aggregation. Surprisingly, a few of the compounds, carbazochrome and niclosamide, appeared to augment Aβ formation. Thus, hydrazides reduced lipid oxidative damage, and hydralazine additionally reduced Aβ misfolding. While hydralazine would require specific chemical modifications for use as an AD therapeutic itself (to improve blood brain barrier permeability, reduce vasoactive side effects, and optimization for amyloid inhibition), this study suggests its potential merit for further AD drug development.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Ian V.J. Murray
- To whom correspondence should be addressed: Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, 142E Reynolds Medical Building, College Station Texas. 77843-1114. Telephone: (979) 458-4355. Fax: 979 845-0790.
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Goux A, Feillet-Coudray C, Jover B, Fouret G, Bargnoux AS, Cassan C, Richard S, Badiou S, Cristol JP. NADPH oxidase activity is associated with cardiac osteopontin and pro-collagen type I expression in uremia. Free Radic Res 2010; 45:454-60. [PMID: 21117892 DOI: 10.3109/10715762.2010.541455] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abstract Cardiovascular disease is a frequent complication inducing mortality in chronic kidney disease (CKD) patients, which can be determined by both traditional risk factors and non-traditional risk factors such as malnutrition and oxidative stress. This study aimed to investigate the role of oxidative stress in uremia-induced cardiopathy in an experimental CKD model. CKD was induced in Sprague-Dawley rats by a 4-week diet supplemented in adenine, calcium and phosphorous and depleted in proteins. CKD was associated with a 3-fold increase in superoxide anion production from the NADPH oxidase in the left ventricle, but the maximal activity of mitochondrial respiratory chain complexes was not different. Although manganese mitochondrial SOD activity decreased, total SOD activity was not affected and catalase or GPx activities were increased, strengthening the major role of NADPH oxidase in superoxide anion output. Superoxide anion output was associated with enhanced expression of osteopontin (×7.7) and accumulation of pro-collagen type I (×3.7). To conclude, the increased activity of NADPH oxidase during CKD is associated with protein modifications which could activate a pathway leading to cardiac remodelling.
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Affiliation(s)
- Aurélie Goux
- UMR 204, Prévention des Malnutritions et des Pathologies Associées, IRD, University Montpellier 1 et 2, Montpellier, France
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16
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Simvastatin improves wound strength after intestinal anastomosis in the rat. J Gastrointest Surg 2009; 13:1707-16. [PMID: 19578821 DOI: 10.1007/s11605-009-0951-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2009] [Accepted: 04/15/2009] [Indexed: 01/31/2023]
Abstract
BACKGROUND Simvastatin is a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor commonly known as a cholesterol-lowering drug with additional pleiotropic effects. Also, it is demonstrated that it prevents postoperative peritoneal adhesions in rat. This study was designed to assess its effects on the healing process of colonic anastomosis. METHODS Thirty-two male Wistar albino rats were randomized into two groups and subjected to colonic anastomosis. The study group was treated with simvastatin and the control group received only tap water instead. The rats were killed 3 and 7 days postoperatively. Wound complications, intra-abdominal abscesses, and anastomotic leaks and stenosis were recorded. Four types of assessment were performed: bursting pressure, hydroxyproline content, histopathology, and biochemical analysis. RESULTS Compared to the control group, simvastatin-treated rats displayed a higher bursting pressure (p < 0.001) and anastomotic hydroxyproline content (p < 0.05). Simvastatin treatment leads to a significant decrease in malondealdehyde levels (p < 0.05) and increase in paraoxonase activity (p < 0.001) at both time points. Histopathological analysis revealed that simvastatin administration leads to a better anastomotic healing in terms of reepithelialization, decreased granuloma formation, reduced ischemic necrosis, and inflammatory infiltration to muscle layer. CONCLUSION Clinically relevant doses of simvastatin do not have a negative impact on colonic anastomosis but improve intestinal wound healing in rats.
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Castro MM, Rizzi E, Rodrigues GJ, Ceron CS, Bendhack LM, Gerlach RF, Tanus-Santos JE. Antioxidant treatment reduces matrix metalloproteinase-2-induced vascular changes in renovascular hypertension. Free Radic Biol Med 2009; 46:1298-307. [PMID: 19248829 DOI: 10.1016/j.freeradbiomed.2009.02.011] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 02/06/2009] [Accepted: 02/10/2009] [Indexed: 02/07/2023]
Abstract
Mounting evidence indicates that structural and functional vascular changes associated with two-kidney, one-clip (2K-1C) hypertension result, at least in part, from altered activity of matrix metalloproteinases (MMPs). Because MMPs are upregulated by increased formation of reactive oxygen species (ROS), we hypothesized that antioxidant approaches could attenuate the increases in MMP-2 expression/activity and the vascular dysfunction and remodeling associated with 2K-1C hypertension. Sham-operated or 2K-1C hypertensive rats were treated with tempol 18 mg/kg/day or apocyanin 25 mg/kg/day (or vehicle). Systolic blood pressure was monitored weekly. After 8 weeks of treatment, aortic rings were isolated to assess endothelium-dependent and -independent relaxation. Quantitative morphometry of structural changes in the aortic wall was studied in hematoxylin/eosin sections. Aortic and systemic ROS levels were measured using dihydroethidine and thiobarbituric acid-reactive substances, respectively. Aortic MMP-2 levels and activity were determined by gelatin and in situ zymography, fluorimetry, and immunohistochemistry. Tempol and apocyanin attenuated 2K-1C hypertension (181+/-20.8 and 192+/-17.6 mm Hg, respectively, versus 213+/-18 mm Hg in hypertensive controls; both p<0.05) and prevented the reduction in endothelium-dependent vasorelaxation found in 2K-1C rats. Tempol, but not apocyanin (p>0.05), prevented the vascular remodeling found in 2K-1C rats (all p<0.01). Tempol was more effective than apocyanin in attenuating hypertension-induced increases in oxidative stress (both p<0.05), MMP-2 levels, and MMP-2 activity in hypertensive rats (all p<0.05). Our results suggest that antioxidant approaches decrease MMP-2 upregulation and attenuate the vascular dysfunction and remodeling during 2K-1C hypertension.
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Affiliation(s)
- Michele M Castro
- Department of Pharmacology, Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirao Preto, SP, Brazil
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Rafikova O, Salah EM, Tofovic SP. Renal and metabolic effects of tempol in obese ZSF1 rats--distinct role for superoxide and hydrogen peroxide in diabetic renal injury. Metabolism 2008; 57:1434-44. [PMID: 18803950 DOI: 10.1016/j.metabol.2008.05.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2007] [Accepted: 05/05/2008] [Indexed: 12/31/2022]
Abstract
Oxidative stress, that is, overproduction of reactive oxygen species and reduced antioxidant system activity, is implicated in the pathogenesis of diabetic complications; and therefore, superoxide dismutase (SOD) mimetic tempol should be protective in diabetic kidney. However, the effects of tempol in metabolic syndrome-associated renal injury have not been thoroughly examined. In this study, we examined the effects of 9 weeks of treatment with tempol on metabolic status, renal oxidative stress, and kidney function and structure in obese, diabetic, hypertensive ZSF(1) rats and their nondiabetic, hypertensive, lean littermates. The obese rats had significantly reduced total SOD and catalase activity, increased peroxidase activity and lipid peroxidation, and higher level of protein oxidation in renal cortical tissue compared with their lean littermates. These changes were accompanied by renal injury (proteinuria; reduced excretory function; and markedly increased glomerular and interstitial inflammation, proliferation, and collagen IV synthesis). Tempol treatment slightly increased total SOD activity, significantly reduced lipid peroxidation and peroxidase activity, but had no effect on catalase and protein oxidation. Tempol had no effects on blood pressure, renal hemodynamics and excretory function, and proteinuria in obese rats, yet improved insulin sensitivity and reduced renal inflammatory, proliferative, and fibrotic changes. Because tempol possesses no catalase activity and, in diabetes, not only SOD but also catalase is inhibited, it is possible that the toxicity of hydrogen peroxide (H(2)O(2)) remains unaltered under tempol treatment. This study suggests that superoxide and H(2)O(2) may have distinct roles in the pathogenesis of diabetic renal injury, with superoxide mainly being involved in inflammatory, proliferative, and fibrotic changes, and H(2)O(2) in glomerular hemodynamics and proteinuria.
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Affiliation(s)
- Olga Rafikova
- Center for Clinical Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
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Liu J, Shen Q, Wu Y. Simvastatin prevents cardiac hypertrophy in vitro and in vivo via JAK/STAT pathway. Life Sci 2008; 82:991-6. [DOI: 10.1016/j.lfs.2008.02.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Revised: 01/23/2008] [Accepted: 02/10/2008] [Indexed: 10/22/2022]
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